A known record/reproduce apparatus for magnetic recording tape includes a two piece, cylindrical scanner assembly. A lower stationary guide drum includes a tape guide element positioned at the entrance of the tape to an upper rotary scanner body mounted on the stationary guide drum so as to be freely rotatable. Magnetic tape is driven around the upper scanner body by the record/reproduce apparatus along a tape path defined by the tape guide and one or more entrance and/or exit guides mounted adjacent the upper scanner body. Depending on the data format and the apparatus configuration, the upper scanner body rotates either counter to or in the direction of tape movement and contains one or more read/write heads which scan the tape at a rate which is normally much higher than the rate of linear tape movement. The apparatus moves the tape medium along a helical path for scanning; in such format the data tracks are positioned obliquely to the longitudinal axis of the tape, to maximize the width of the individual data tracks per width of tape. To align the data tracks of the tape for movement across the heads in the scanning drum the tape must follow a helical path around the scanning drum.
With respect to both component and composite digital formats the read/write transducers mounted in the scanning drum are mounted in pairs to substantially reduce the cost and complexity of such mechanism. Typically the head pairs are disposed at a scanning window provided in the upper scanner body. Moreover, with respect to the recording or transmission of television signals, with substantially high multiples of tracks required for each television field, particularly in variable speed playback applications, each head pair sharing a common window experiences Automatic Scan Tracking (AST) deflections in rapid reciprocal movement (dithering) across the entire width of the scanning window to satisfy AST deflection requirements. Those AST deflections are large and necessitate a relatively wide scanner opening for the record/ playback head pair. Moreover, typical scanner opening/head structure requirements which produce satisfactory head to tape contact using older and thicker magnetic tapes produce less predictable results when a thinner tape, such as normally used for digital applications, is used, particularly when a head pair is deflected to one side of the scanner opening.
Although there are known structures which place obstacles between the head and the scanner body to modify the head-to-tape interface; for example, in the Japanese publication 56-94539, "Cylindrical Body For Fitting Of Rotating Magnetic Head", there is no known structure which provides a means for supporting the tape between a pair of separated scanner heads. Moreover, the known structures fail to attach any significance to the problem of loss of signal output. Accordingly, such structures have little bearing on the structure and performance of the present invention.